Byoungsoo Lee

Control Oriented Storage and Reduction Modeling of the Lean NO x Trap Catalyst

A control oriented model of the Lean NOx trap (LNT) was developed to determine the timing of NOx regeneration. The LNT model consists of NOx storage and reduction model. Once NOx is stored (NOx storage model), at the right timing NOx should be released and then reduced (NOx reduction model) with reductants on the catalyst active sites, called regeneration. The NOx storage model simulates the degree of stored NOx in the LNT. It is structured by an instantaneous NOx storage efficiency and the NOx storage capacity model. The NOx storge capacity model was modeled to have a Gaussian distribution with a function of exhaust gas temperature. NOx release and reduction reactions for the NOx reduction model were modeled as Arrhenius equations. The parameter identification was optimally performed by the data of the bench flow reactor test results at space velocity 50,000/hr, 80,000/hr, and temperature of 250 - 500°C. The LNT model state, storage fraction indicates the degree of stored NO x in the LNT and thus, the timing of the regeneration can be determined based on it. For practical purpose, this model will be verified more completely by engine test data which simulate the NEDC transient mode.

Automatic Swing Door for a Passenger Car by Using Parallel Force/Velocity Actuator (PFVA)

A vehicles door is frequently used by a driver or passengers. When a vehicle is parked at incline, it is not easy to open or close doors because of gravity force and external disturbances. Moreover, there might cause a safety problems for a weak or a disabled person. Therefore, there is increasing demand for automation of vehicles door. In this study, an automatic swing door mechanism for a passenger car is proposed by using a parallel force/velocity actuator (PFVA) based on a Dual-Input-Single-Output (DISO) framework. PFVA has two distinct actuators. One is force actuator(FA) with a low reduction gear train, the other is velocity actuator(VA) with a high reduction gear train. It can be effectively used in combining velocity control with force compensation application. First, we formulated a kinematics and a dynamics of automatic swing door system with PFVA as input, and then a simulation environment was developed for a feasibility test by using a kinematic and a dynamic model. Finally, a velocity control with force compensation was performed by using the developed simulation environment. VA was faithfully followed a reference velocity trajectory for opening and closing a door, and FA was able to compensate a gravity torque and an inertial disturbance torque coming from the VA.

Velocity Control and Collision Detection by Feedback Linearization for an Power-assisted Automotive Swing Door

Automatic swing door for an automotive application is considered. The equation of motion for a driver side swing door is introduced and gravity cancellation control scheme is adapted. The control scheme supposed to cancel the moment due to the tilt of the car. A speed control is suggested for door operation automation but the output of the speed control is not suppose to be precise as for the manufacturing system control. In the frame of the velocity control of the door, feedback linearization was applied for collision detection. The collision detection performance is satisfactory. The estimate of the magnitude of disturbance due to the collision is close to the actual magnitude of disturbance. Simulation study has been performed to gain insight into the system behavior. Also real test on the prototype hardware has been performed for verification purpose.